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| author | Viresh Kumar <viresh.kumar@linaro.org> | 2017-07-19 13:12:46 +0300 |
|---|---|---|
| committer | Rafael J. Wysocki <rafael.j.wysocki@intel.com> | 2017-07-26 01:15:45 +0300 |
| commit | ed4676e254630c1f00a4fc8f3821890fff7e3643 (patch) | |
| tree | 5cedac1abae32d5bbdde7585bbe915ff036c581c | |
| parent | 768608a578255c0add26bfdcb720d320eca1556b (diff) | |
| download | linux-ed4676e254630c1f00a4fc8f3821890fff7e3643.tar.xz | |
cpufreq: Replace "max_transition_latency" with "dynamic_switching"
There is no limitation in the ondemand or conservative governors which
disallow the transition_latency to be greater than 10 ms.
The max_transition_latency field is rather used to disallow automatic
dynamic frequency switching for platforms which didn't wanted these
governors to run.
Replace max_transition_latency with a boolean (dynamic_switching) and
check for transition_latency == CPUFREQ_ETERNAL along with that. This
makes it pretty straight forward to read/understand now.
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 8 | ||||
| -rw-r--r-- | drivers/cpufreq/cpufreq_governor.h | 2 | ||||
| -rw-r--r-- | include/linux/cpufreq.h | 9 |
3 files changed, 7 insertions, 12 deletions
diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index c426d21822f7..88139e5e87da 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2003,13 +2003,13 @@ static int cpufreq_init_governor(struct cpufreq_policy *policy) if (!policy->governor) return -EINVAL; - if (policy->governor->max_transition_latency && - policy->cpuinfo.transition_latency > - policy->governor->max_transition_latency) { + /* Platform doesn't want dynamic frequency switching ? */ + if (policy->governor->dynamic_switching && + policy->cpuinfo.transition_latency == CPUFREQ_ETERNAL) { struct cpufreq_governor *gov = cpufreq_fallback_governor(); if (gov) { - pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", + pr_warn("Transition latency set to CPUFREQ_ETERNAL, can't use %s governor. Fallback to %s governor\n", policy->governor->name, gov->name); policy->governor = gov; } else { diff --git a/drivers/cpufreq/cpufreq_governor.h b/drivers/cpufreq/cpufreq_governor.h index 95f207eb820e..8463f5def0f5 100644 --- a/drivers/cpufreq/cpufreq_governor.h +++ b/drivers/cpufreq/cpufreq_governor.h @@ -159,7 +159,7 @@ void cpufreq_dbs_governor_limits(struct cpufreq_policy *policy); #define CPUFREQ_DBS_GOVERNOR_INITIALIZER(_name_) \ { \ .name = _name_, \ - .max_transition_latency = TRANSITION_LATENCY_LIMIT, \ + .dynamic_switching = true, \ .owner = THIS_MODULE, \ .init = cpufreq_dbs_governor_init, \ .exit = cpufreq_dbs_governor_exit, \ diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index aaadfc543f63..e141dbbb9d1c 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -487,12 +487,8 @@ static inline unsigned long cpufreq_scale(unsigned long old, u_int div, * polling frequency is 1000 times the transition latency of the processor. The * ondemand governor will work on any processor with transition latency <= 10ms, * using appropriate sampling rate. - * - * For CPUs with transition latency > 10ms (mostly drivers with CPUFREQ_ETERNAL) - * the ondemand governor will not work. All times here are in us (microseconds). */ #define LATENCY_MULTIPLIER (1000) -#define TRANSITION_LATENCY_LIMIT (10 * 1000 * 1000) struct cpufreq_governor { char name[CPUFREQ_NAME_LEN]; @@ -505,9 +501,8 @@ struct cpufreq_governor { char *buf); int (*store_setspeed) (struct cpufreq_policy *policy, unsigned int freq); - unsigned int max_transition_latency; /* HW must be able to switch to - next freq faster than this value in nano secs or we - will fallback to performance governor */ + /* For governors which change frequency dynamically by themselves */ + bool dynamic_switching; struct list_head governor_list; struct module *owner; }; |